Fuel system is to lean
 

I have a pretty much stock 1989 5.0 LX Converible. Accept for Mac Headers, X-pipe and a Hyper Tech Chip. I am getting 41 and 91 codes when running a KOER test. The car stumbles. The car has a new map sensor, fuel pump, O2 sensors, and EEC IV. My mass air flow seems to pass its test. The fuel pressure under load is 39. Under load for a while and then release indicates 39 and can drop down to 35. What do you guys think?

Any one out there please help?
 

Please help?

How do the plugs look? Have you checked for a vacuum leak?

Take care,
~Chris

I have brand new plugs and cap. Should I get new wires?

No. I was asking how the plugs looked to see if they looked like the system was lean. Check for a vacuum leak.

Take care,
~Chris

I will chech plugs today.
 

I am blowing white smoke out of both tail pipes. To check for vacuum do I need to listen for it or buy a gage. I have pulled the vaccum line off the fuel pressure regulator and it seems pretty strong.:D

white smoke well either your burning tranny fluid or coolant no vacuum modulator on an aod so i bet it's gonna be coolant pull your plugs to see if any of them are wet or if water comes out and check to see if there is water in your oil also look behind or under the car (whichever the case may be) to see if you have a coolant puddle at the end of the tailpipe i bet you have a blown head gasket(most likely) or possibly a tiny ultra microscopic crack in your #6 intake runner at which time you will pull your heads off and look at the head gaskets and say hmmm they look ok then you disassemble your heads and see nothing so you put it back together and it still does the same thing smoking like a freight train (this happened to me) seriously though i bet it's a head gasket.

Re: I will chech plugs today.
 

This adds an important twist. Are there any signs of water in the oil? You should perform a compression test.

Take care,
~Chris

I just remembered that I over filled the coolant. Thats why I had white smoke. I just checked my plugs and they are black/grey and kind of charcoled. What vacuum line do I need to test?

1) Overfilling the coolant won't produce white smoke from your tailpipes. You should still do a compression test.

2) Your plugs do not exhibit the signs of a lean burning engine.

Take care,
~Chris

No white smoke.
 

I checked the car out when I was driving. There was no white smoke. I still think the car was pushing the extra coolant fluid that I put in to the fill take out. I don't know how to check for vacuum? I will check my compression tomorrow. When I go to the shop. I noticed the other day that my hose leading from the air pump to the x pipe has fallen off. I pluged the mac off road x pipe up with a bolt. I going to run a KOER test again also and get ride smog pump soon. I also need to put new mufflers and tail pipes on the car.

Start over again. This goes in too many directions. Reset your ECM by disconnecting the negative battery cable, turning on the headlight switch for 10 minutes, turning it off, and reconnecting the battery cable. Then pull KOEO codes. If you get an 11, then go ahead and pull the KOER codes. If you don't get an 11, then post the codes you do get. ALSO, post a history of what you've done, what you've noticed, and the results of any testing you have done.

Take care,
~Chris

Starting over!
 

I had the NDS installed on my car so that I have to hit the switch when I want to drive. I couldn't get to the NDS without taking the transmission out of the car. I took the hypertech chip out put the lights on took the positive off the car for over ten minutes. I unplugged the computer also. These are the codes I pulled on the first KOEO test today doing a KOEO test. 67 because I must of not hit the switch correctly, 64, 66, 96, 95. I couldn't run a KOER test because it said I had some hard codes to address. 98 & 66. What do you guys think. I will get the NDS done correctly when I have to take the transmission out to redo the rear main. What avenue to I need to take before that?

You need to disconnect the negative battery cable, not the positive, for ten minutes, AND have the headlight switch on during that time, then reattach the cable, and run KOEO. The reason for this is to drain any capacitors in the system. You came up with continuous codes, which means you didn't reset the ECM. Try again.

Take care,
~Chris

I disconnected the ECM
 

Doesn't that do the same thing.

No. You have codes present that can only be triggered by having the engine run, and since it hasn't run since the ECM was "reset", the codes didn't clear.

Take care,
~Chris

I cleared the codes like you asked.
 

So I scanned the new codes doing an KOER and they were the codes I came up with before. 41, 91. System is lean on both sides of the exhaust. I did an KOEO test it was 85. Canister perge. I still think our best path of diagonist is the codes that I got before 64, 66, 95 and 96. I have not had a check engine light on since I broke down yesterday. The KOEO codes that I got yesterday were 64, 66, 95 and 96. PKRWUD you know alot more about this than I do. So your advice is much appreciated. I sure appreciate OBD2 now. What do you think about OBD2?

You're not following my directions very well. This is going to be my last post if that continues.

YOUR JOB:

Reattach the hose to your exhaust.

Replace your ACT (Air Charge Temp) sensor.

RESET THE ECM EXACTLY LIKE I TOLD YOU TO BEFORE.

Start the engine, and let it idle. Go around the car wiggling the wiring harness going to the fuel pump, and listen for a miss or a stall.

If none, replace your fuel pump relay, and inspect the wires going to it.

Inspect the wiring to the MAF.

If they look good, RESET THE ECM ONE MORE TIME, JUST LIKE I TOLD YOU to, and run KOEO TEST ONLY!!!

If there is ANYTHING other than a passing code, STOP, post your results, and WAIT until you hear from me. DO NOT DO ANOTHER KOER TEST UNDER ANY CIRCUMSTANCES, UNLESS IT PASSES KOEO.

Wiggle test
 

Can I run the wiggle test on my OTC Scanner? I just bought a new a new ACT sensor. I bought a new on about a year ago. The orginal one was bent over. I'm sorry I made you so mad earlier.

listen up man
 

If you follow PKRWUD's directions he will help you out and you will be very happy with solving you problems.

Chris (AKA PKRWUD) is very knowledgable and if you don't help him he can't help you!

Good luck with your problems

Conrad

Test finished
 

So I hooked up the smog pump. Put a new ACT sensor in the car. Disconnected the negative battery cable and turned on the light switch for way over ten minutes. The I looked at the MAF wiring harnes. It looks fine. Started up the car and did a wiggle test. Wiggled on the wires under the dash by the driver side and by the gas tank. I couldn't get the car to start missing. I ran a code scanner and I passed the KOEO test. The place that I paid to do some work replaced the fuel pump relay and cleaned up the wiring side of the connector. Right now I am a little disturbed and lost.

So you passed the KOEO test which means that all of your sensors passed the quick test. Now it's time to run the KOER test as Chris suggested. Let us know what the results are.

KOER
 

Do I need to reset the computer? Can I run a KOER test while doing a wiggle test. Last time I ran a KOER test. The scanner said that I was running a lean in both banks. Should I do a Key On Engine Running while I drive the car. I am very open to suggestions.

Thank you,
grant66

KOER TEST
 

I am going to run a KOER test in the mourning. I will post.

Results from this mournings test
 

I ran a KOER test and OTC scanner came up with 41 and 91. Fuel injection system is lean on both banks. I also ran a KOER wiggle test with the OTC scanner I got nothing back. Does any one have any ideas?

Thank you,

grant66

Have you removed the Hypertech chip, yet? If not, I suggest you try that. Clear your codes and then do the KOER test again.

Hypertech chip
 

About a week ago I cleared the codes. Took out the chip. Removed the computer and hooked up the scanner. I still received code 41 and 91. I will try it again. If that is what you suggest. Is there any specific test on any sensor that you would like me to do?

Thank you,

grant66

Okay, next you need to run the engine at 2000 rpms for 4 minutes, shut it off, wait 10 seconds, and rerun KOER test again. What codes come up?

Results to KOER
 

So I first disconnected the negative post to the battery for eleven minuites and turned on the head light switch to reset the codes. (I don't believe this matters because we didn't have any hard codes in the computer) I took the hypertech chip out of the car. Ran the car for 4 minuites at 2000 RPMS. I then shut the car down for 10 seconds. The next thing I did was started the KOER test with the OTC scanner. The scanner ran me throught KOER test and came up with the 21, 41 and 91.

Re: Results to KOER
 

All I asked you to do was run it at 2000 rpms for 4 minutes, and rerun KOER.

Your problem is in one of 3 areas. You either have a fuel pressure problem, a vacuum leak, or a problem with the O2 sensors and/or their wiring. There is only one more test that you will be able to do as far as your sensors are concerned, and that is to check them to see if they can generate the necessary voltage. To determine this, you need to disconnect an O2 sensor, and attach a DMM pos lead to the signal wire from the sensor (either the dark blue/light green wire, or the dark green/pink wire), and the DMM neg lead to the neg battery post. Then run KOER, and monitor the DMM. If the voltage is over .5 vdc, then the sensor is good. If the voltage stays below .5 vdc, then the sensor needs to be replaced. After testing one, test the other.

Did you already check your fuel pressure?

The wiring to O2 sensor
 

I have brand new O2 sensors. The guys at Stang Auto Tech said every thing is good with oxygen sensors and the wiring leading up to the O2's. I didn't understand what the DMM is? The car has new sensors except for the mass air flow. The last time I tested it seemed to be in the vacinity of its ranges.

I need a place to start in the wiring. I only have an analog meter. It sounds like I need to invest into a digital Volt Olm meter. What do you think?

I couldn't find any thing wrong with fuel pressure when the car is working correctly. I don't know about it when it fails to work or get under load for long periods of time.

The car doesn't like to be very warm for long periods of time.

How about those codes I get after the car doesn't want to work?
Can they lead me into any direction?

The other codes were for the ACT sensor, which you replaced, the MAF, which you said tested good, and that it's wires looked good, and the fuel pump circuit, which you serviced with a new relay, and by checking the wiring. Unless those codes come up as current, there is no way to determine the source of them, other than what you've already done. The codes that are current are 41 & 91, so those are the only codes we have to work with. If your mechanic says the O2 sensors and wiring are good, then that leaves fuel pressure or a vacuum leak. You said the fuel pressure tested okay, which leaves a vacuum leak. A vacuum leak would create a high idle that wouldn't change much when you created a new vacuum leak. You said you inspected the vacuum hoses, and didn't find any problems. You have eliminated all of the possibilities.

The reason why I suspect the problem may be in the O2 sensors or their wiring is because the spark plugs didn't read lean. If the system was lean, from either a vacuum leak or a lack of fuel, your spark plugs would be bright white, but they weren't. That makes me think that things are fine, but the O2 sensor circuit thinks, for whatever reason, that things are not fine. Odds are you have a bad ground contact somewhere.

My recommendation is to go to your mechanic, and have him diagnose it for you. I really don't know what else to tell you to do. According to you, you've passed all the tests.

Take care,
~Chris

Speaking of bad ground wires for O2 sensors, you have that orange wire with the eyelet on the end hooked up to the block somehow, don't you? It's located toward the back and has a black, cloth cover on it.

O2 sensor grounds?
 

What side of the block are the O2 sensor grounds on? How do I do some of the fuel pressure tests? Not hooking up the gauge, but procedures and starting points. Is there guages for checking vacuum leaks. What is the DMM mentioned by PRKWUD. I want to check the HEGO's Maybe hook up new wiring for the HEGO's. Is there a harness that I can purchase. Has anyone redone their wiring to the O2 sensors? I am very lost!